Micronutrients at Supplemental Levels, Tight Junctions and Epithelial Barrier Function: A Narrative Review.

Disease modifiers, whether from cancer, sepsis, systemic inflammation, or microbial pathogens, all appear to induce epithelial barrier leak, with induced changes of the Tight Junctional (TJ) complex being pivotal to the process. This leak-and the ensuant breakdown of compartmentation-plays a central role in disease morbidity on many levels. Accumulation of lung water in the luminal compartment of airways was a major driver of morbidity and mortality in COVID-19 and is an excellent example of the phenomenon. Increasing awareness of the ability of micronutrients to improve basal barrier function and reduce barrier compromise in pathophysiology may prove to be a low-cost, safe, and easily administered prophylactic and/or therapeutic option amenable to large populations. The growing appreciation of the clinical utility of supplemental doses of Vitamin D in COVID-19 is but one example. This narrative review is intended to propose a general theory on how and why micronutrients-at levels above normal dietary intake-successfully remodel TJs and improve barrier function. It discusses the key difference between dietary/Recommended Daily Allowance (RDA) levels of micronutrients versus supplemental levels, and why the latter are needed in disease situations. It advances a hypothesis for why signal transduction regulation of barrier function may require these higher supplemental doses to achieve the TJ remodeling and other barrier element changes that are clinically beneficial.

Anisomeles indica Extracts and Their Constituents Suppress the Protein Expression of ACE2 and TMPRSS2 In Vivo and In Vitro.

Coronavirus disease 2019 (COVID-19), stemming from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has had a profound global impact. This highly contagious pneumonia remains a significant ongoing threat. Uncertainties persist about the virus's effects on human health, underscoring the need for treatments and prevention. Current research highlights angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) as key targets against SARS-CoV-2. The virus relies on ACE2 to enter cells and TMPRSS2 to activate its spike protein. Inhibiting ACE2 and TMPRSS2 expression can help prevent and treat SARS-CoV-2 infections. Anisomeles indica (L.) Kuntze, a medicinal plant in traditional Chinese medicine, shows various promising pharmacological properties. In this study, ethanolic extracts of A. indica were examined both in vivo (250 and 500 µM) and in vitro (500 µM). Through Western blotting analysis, a significant reduction in the expression levels of ACE2 and TMPRSS2 proteins was observed in HepG2 (human hepatocellular carcinoma) cells and HEK 293T (human embryonic kidney) cell lines without inducing cellular damage. The principal constituents of A. indica, namely, ovatodiolide (5 and 10 µM), anisomlic acid (5 and 10 µM), and apigenin (12.5 and 25 µM), were also found to produce the same effect. Furthermore, immunohistochemical analysis of mouse liver, kidney, and lung tissues demonstrated a decrease in ACE2 and TMPRSS2 protein expression levels. Consequently, this article suggests that A. indica and its constituents have the potential to reduce ACE2 and TMPRSS2 protein expression levels, thus aiding in the prevention of SARS-CoV-2 infections.

The Emerging Role of MAIT Cell Responses in Viral Infections.

Mucosal-associated invariant T (MAIT) cells are unconventional T cells with innate-like antimicrobial responsiveness. MAIT cells are known for MR1 (MHC class I-related protein 1)-restricted recognition of microbial riboflavin metabolites giving them the capacity to respond to a broad range of microbes. However, recent progress has shown that MAIT cells can also respond to several viral infections in humans and in mouse models, ranging from HIV-1 and hepatitis viruses to influenza virus and SARS-CoV-2, in a primarily cognate Ag-independent manner. Depending on the disease context MAIT cells can provide direct or indirect antiviral protection for the host and may help recruit other immune cells, but they may also in some circumstances amplify inflammation and aggravate immunopathology. Furthermore, chronic viral infections are associated with varying degrees of functional and numerical MAIT cell impairment, suggesting secondary consequences for host defense. In this review, we summarize recent progress and highlight outstanding questions regarding the emerging role of MAIT cells in antiviral immunity.

Cytokine Storm in Acute Viral Respiratory Injury: Role of Qing-Fei-Pai-Du Decoction in Inhibiting the Infiltration of Neutrophils and Macrophages through TAK1/IKK/NF-[Formula: see text]B Pathway.

COVID-19 has posed unprecedented challenges to global public health since its outbreak. The Qing-Fei-Pai-Du decoction (QFPDD), a Chinese herbal formula, is widely used in China to treat COVID-19. It exerts an impressive therapeutic effect by inhibiting the progression from mild to critical disease in the clinic. However, the underlying mechanisms remain obscure. Both SARS-CoV-2 and influenza viruses elicit similar pathological processes. Their severe manifestations, such as acute respiratory distress syndrome (ARDS), multiple organ failure (MOF), and viral sepsis, are correlated with the cytokine storm. During flu infection, QFPDD reduced the lung indexes and downregulated the expressions of MCP-1, TNF-[Formula: see text], IL-6, and IL-1[Formula: see text] in broncho-alveolar lavage fluid (BALF), lungs, or serum samples. The infiltration of neutrophils and inflammatory monocytes in lungs was decreased dramatically, and lung injury was ameliorated in QFPDD-treated flu mice. In addition, QFPDD also inhibited the polarization of M1 macrophages and downregulated the expressions of IL-6, TNF-[Formula: see text], MIP-2, MCP-1, and IP-10, while also upregulating the IL-10 expression. The phosphorylated TAK1, IKK[Formula: see text]/[Formula: see text], and I[Formula: see text]B[Formula: see text] and the subsequent translocation of phosphorylated p65 into the nuclei were decreased by QFPDD. These findings indicated that QFPDD reduces the intensity of the cytokine storm by inhibiting the NF-[Formula: see text]B signaling pathway during severe viral infections, thereby providing theoretical and experimental support for its clinical application in respiratory viral infections.

Beneficial or detrimental activity of regulatory T cells, indoleamine 2,3-dioxygenase, and heme oxygenase-1 in the lungs is influenced by the level of virulence of Mycobacterium tuberculosis strain infection.

Tuberculosis (TB) caused by the complex Mycobacterium tuberculosis (Mtb) is the main cause of death by a single bacterial agent. Last year, TB was the second leading infectious killer after SARS-CoV-2. Nevertheless, many biological and immunological aspects of TB are not completely elucidated, such as the complex process of immunoregulation mediated by regulatory T cells (Treg cells) and the enzymes indoleamine 2,3-dioxygenase (IDO) and heme oxygenase 1 (HO-1). In this study, the contribution of these immunoregulatory factors was compared in mice infected with Mtb strains with different levels of virulence. First Balb/c mice were infected by intratracheal route, with a high dose of mild virulence reference strain H37Rv or with a highly virulent clinical isolate (strain 5186). In the lungs of infected mice, the kinetics of Treg cells during the infection were determined by cytofluorometry and the expression of IDO and HO-1 by RT-PCR and immunohistochemistry. Then, the contribution of immune-regulation mediated by Treg cells, IDO and HO-1, was evaluated by treating infected animals with specific cytotoxic monoclonal antibodies for Treg cells depletion anti-CD25 (PC61 clone) or by blocking IDO and HO-1 activity using specific inhibitors (1-methyl-D,L-tryptophan or zinc protoporphyrin-IX, respectively). Mice infected with the mild virulent strain showed a progressive increment of Treg cells, showing this highest number at the beginning of the late phase of the infection (28 days), the same trend was observed in the expression of both enzymes being macrophages the cells that showed the highest immunostaining. Animals infected with the highly virulent strain showed lower survival (34 days) and higher amounts of Treg cells, as well as higher expression of IDO and HO-1 one week before. In comparison with non-treated animals, mice infected with strain H37Rv with depletion of Treg cells or treated with the enzymes blockers during late infection showed a significant decrease of bacilli loads, higher expression of IFN-g and lower IL-4 but with a similar extension of inflammatory lung consolidation determined by automated morphometry. In contrast, the depletion of Treg cells in infected mice with the highly virulent strain 5186 produced diffuse alveolar damage that was similar to severe acute viral pneumonia, lesser survival and increase of bacillary loads, while blocking of both IDO and HO-1 produced high bacillary loads and extensive pneumonia with necrosis. Thus, it seems that Treg cells, IDO and HO-1 activities are detrimental during late pulmonary TB induced by mild virulence Mtb, probably because these factors decrease immune protection mediated by the Th1 response. In contrast, Treg cells, IDO and HO-1 are beneficial when the infection is produced by a highly virulent strain, by regulation of excessive inflammation that produced alveolar damage, pulmonary necrosis, acute respiratory insufficiency, and rapid death.

Targeting the MR1-MAIT cell axis improves vaccine efficacy and affords protection against viral pathogens.

Mucosa-associated invariant T (MAIT) cells are MR1-restricted, innate-like T lymphocytes with tremendous antibacterial and immunomodulatory functions. Additionally, MAIT cells sense and respond to viral infections in an MR1-independent fashion. However, whether they can be directly targeted in immunization strategies against viral pathogens is unclear. We addressed this question in multiple wild-type and genetically altered but clinically relevant mouse strains using several vaccine platforms against influenza viruses, poxviruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We demonstrate that 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU), a riboflavin-based MR1 ligand of bacterial origin, can synergize with viral vaccines to expand MAIT cells in multiple tissues, reprogram them towards a pro-inflammatory MAIT1 phenotype, license them to bolster virus-specific CD8+ T cell responses, and potentiate heterosubtypic anti-influenza protection. Repeated 5-OP-RU administration did not render MAIT cells anergic, thus allowing for its inclusion in prime-boost immunization protocols. Mechanistically, tissue MAIT cell accumulation was due to their robust proliferation, as opposed to altered migratory behavior, and required viral vaccine replication competency and Toll-like receptor 3 and type I interferon receptor signaling. The observed phenomenon was reproducible in female and male mice, and in both young and old animals. It could also be recapitulated in a human cell culture system in which peripheral blood mononuclear cells were exposed to replicating virions and 5-OP-RU. In conclusion, although viruses and virus-based vaccines are devoid of the riboflavin biosynthesis machinery that supplies MR1 ligands, targeting MR1 enhances the efficacy of vaccine-elicited antiviral immunity. We propose 5-OP-RU as a non-classic but potent and versatile vaccine adjuvant against respiratory viruses.

Micronutrients, genetics and COVID-19.

PURPOSE OF REVIEW: Marked inter-individual differences in the clinical manifestation of coronavirus disease 2019 (COVID-19) has initiated studies in the field of genetics. This review evaluates recent genetic evidence (predominantly in the last 18 months) related to micronutrients (vitamins and trace elements) and COVID-19. RECENT FINDINGS: In patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), altered circulating levels of micronutrients may serve as prognostic markers of disease severity. Mendelian randomization (MR) studies did not find significant effect of variable genetically predicted levels of micronutrients on COVID-19 phenotypes, however, recent clinical studies on COVID-19 point out to vitamin D and zinc supplementation as a nutritional strategy to reduce disease severity and mortality. Recent evidence also points to variants in vitamin D receptor ( VDR ) gene, most notably rs2228570 (FokI) "f" allele and rs7975232 (ApaI) "aa" genotype as poor prognostic markers. SUMMARY: Since several micronutrients were included in the COVID-19 therapy protocols, research in the field of nutrigenetics of micronutrients is in progress. Recent findings from MR studies prioritize genes involved in biological effect, such as the VDR gene, rather than micronutrient status in future research. Emerging evidence on nutrigenetic markers may improve patient stratification and inform nutritional strategies against severe COVID-19.

Esculin alleviates LPS-induced acute lung injury via inhibiting neutrophil recruitment and migration.

OBJECTIVES: Acute lung injury (ALI) poses a serious threat to human health globally, particularly with the Coronavirus 2019 (COVID-19) pandemic. Excessive recruitment and infiltration of neutrophils is the major etiopathogenesis of ALI. Esculin, also known as 6,7-dihydroxycoumarin, is a remarkable compound derived from traditional Chinese medicine Cortex fraxini. Accumulated evidence indicates that esculin has potent anti-inflammatory effects, but its pharmaceutical effect against ALI and potential mechanisms are still unclear. METHODS: This study evaluated the protective effect of esculin against ALI by histopathological observation and biochemical analysis of lung tissues and bronchoalveolar lavage fluid (BALF) in lipopolysaccharide (LPS)-challenged ALI mice in vivo. The effects of esculin on N-formyl-met-leu-phe (fMLP)-induced neutrophil migration and chemotaxis were quantitatively assessed using a Transwell assay and an automated cell imaging system equipped with a Zigmond chamber, respectively. The drug affinity responsive target stability (DARTS) assay, in vitro protein binding assay and molecular docking were performed to identify the potential therapeutic target of esculin and the potential binding sites and pattern. RESULTS: Esculin significantly attenuated LPS-induced lung pathological injury, reduced the levels of pro-inflammatory cytokines in both BALF and lung, and suppressed the activation of NF-κB signaling. Esculin also significantly reduced the number of total cells and neutrophils as well as myeloperoxidase (MPO) activity in the BALF. Esculin impaired neutrophil migration and chemotaxis as evidenced by the reduced migration distance and velocity. Furthermore, esculin remarkably inhibited Vav1 phosphorylation, suppressed Rac1 activation and the PAK1/LIMK1/cofilin signaling axis. Mechanistically, esculin could interact with ß2 integrin and then diminish its ligand affinity with intercellular adhesion molecule-1 (ICAM-1). CONCLUSIONS: Esculin inhibits ß2 integrin-dependent neutrophil migration and chemotaxis, blocks the cytoskeletal remodeling process required for neutrophil recruitment, thereby contributing to its protective effect against ALI. This study demonstrates the new therapeutic potential of esculin as a novel lead compound.

Colostrum Antibodies and Cytokines in Puerperal Women with Diabetes Before and During the COVID-19 Pandemic: A Systematic Review.

BACKGROUND: Breastfeeding maintains the maternal-fetal immune link after birth, favors the transmission of immunological competence, and is considered an important contributing factor to the development of the babies' immune system. OBJECTIVE: This study aimed to obtain data related to the effects of gestational diabetes on immunoglobulin A (IgA) and cytokines levels in the colostrum, before and during the pandemic of the new coronavirus, in order to study the possible outcomes regarding the immunological characteristics of human milk. METHODS: This systematic review was registered in PROSPERO CRD42020212397, and the question elaborated using the PICO strategy was: does maternal hyperglycemia associated or not with Covid-19 influence the immunological composition of colostrum? Electronic searching and reference lists of published reports were used to identify studies that reported the influence of gestational diabetes on colostrum and milk composition. RESULTS: Seven studies were selected from the 51 found, six of them were cross-sectional and one was a case report. Six studies included Brazilian groups and only one was conducted in USA. The mothers with gestational diabetes presented a reduced level of IgA and other immunoreactive proteins in colostrum. Those alterations could be related to changes in macronutrient metabolism and cellular oxidative metabolism. CONCLUSION: It was possible to conclude that diabetes changes the immunological composition of breast milk; however, data on the impact of the association between gestational diabetes and Covid-19 infection on the composition of antibodies and cytokines present in human milk are still scarce and inconclusive.

Xuanfei Baidu Decoction regulates NETs formation via CXCL2/CXCR2 signaling pathway that is involved in acute lung injury.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening symptoms in Coronavirus Disease 2019 (COVID-19) patients. Xuanfei Baidu Decoction (XFBD) is a recommend first-line traditional Chinese medicine (TCM) formula therapeutic strategy for COVID-19 patients. Prior studies demonstrated the pharmacological roles and mechanisms of XFBD and its derived effective components against inflammation and infections through multiple model systems, which provided the biological explanations for its clinical use. Our previous work revealed that XFBD inhibited macrophages and neutrophils infiltration via PD-1/IL17A signaling pathway. However, the subsequent biological processes are not well elucidated. Here, we proposed a hypothesis that XFBD can regulate the neutrophils-mediated immune responses, including neutrophil extracellular traps (NETs) formation and the generation of platelet-neutrophil aggregates (PNAs) after XFBD administration in lipopolysaccharide (LPS)-induced ALI mice. The mechanism behind it was also firstly explained, that is XFBD regulated NETs formation via CXCL2/CXCR2 axis. Altogether, our findings demonstrated the sequential immune responses of XFBD after inhibiting neutrophils infiltration, as well as shedding light on exploiting the therapy of XFBD targeting neutrophils to ameliorate ALI during the clinical course.

The effect of vitamin C supplementation on favipiravir-induced oxidative stress and proinflammatory damage in livers and kidneys of rats.

Background: Favipiravir (FPV), an effective antiviral agent, is a drug used to treat influenza and COVID-19 by inhibiting the RNA-dependent RNA polymerase (RdRp) of RNA viruses. FPV has the potential to increase oxidative stress and organ damage. The purpose of this study was to demonstrate the oxidative stress and inflammation caused by FPV in the liver and kidneys of rats, as well as to investigate the curative effects of vitamin C (VitC).Methods: A total of 40 Sprague-Dawley male rats were randomly and equally divided into the following five groups: 1st; Control, 2nd; FPV = 20 mg/kg, 3rd; FPV = 100 mg/kg, 4th; FPV = 20 mg/kg + VitC (150 mg/kg), and 5th; FPV = 100 mg/kg + VitC (150 mg/kg) groups. Rats were given either FPV (orally) or FPV plus VitC (intramuscular) for 14 days. Rat blood, liver, and kidney samples were collected at 15 days to be analyzed for oxidative and histological changes.Results: FPV administration resulted in an increase in proinflammatory cytokines (TNF-α and IL-6) in the liver and kidney, as well as oxidative and histopathologic damage. FPV increased TBARS levels significantly (p < .05) and decreased GSH and CAT levels in liver and kidney tissues but had no effect on SOD activity. VitC supplementation significantly reduced TNF-a, IL-6, and TBARS levels while increasing GSH and CAT levels (p < .05). Furthermore, VitC significantly attenuated FPV-induced histopathological alterations associated with oxidative stress and inflammation in the liver and kidney tissues (p < .05).Conclusion: FPV caused liver and kidney damage in rats. In contrast, co-administration of FPV with VitC improved FPV-induced oxidative, pro-inflammatory, and histopathological changes.

Amelioration of Lung Fibrosis by Total Flavonoids of Astragalus via Inflammatory Modulation and Epithelium Regeneration.

Idiopathic Pulmonary Fibrosis (IPF) is identifiable by the excessive increase of mesenchyme paired with the loss of epithelium. Total flavonoids of Astragalus (TFA), the main biologically active ingredient of the traditional Chinese medicine, Astragalus membranaceus (Huangqi), shows outstanding effects on treating pulmonary disorders, including COVID-19-associated pulmonary dysfunctions. This study was designed to evaluate the efficacy of TFA on treating pulmonary fibrosis and the possible mechanisms behind these effects. A549 cells were treated with TGF-[Formula: see text]1 and TFA to observe the potential effects of TFA on regulating alveolar epithelial cell proliferation, TGF-[Formula: see text]1-induced EMT, and the underlying mechanisms in vitro. Then, mouse pulmonary fibrosis was induced with a single intra-tracheal injection of bleomycin, and TFA was administrated by i.p. injection. Lung fibrosis was evaluated through histological and molecular analyses, and the possible mechanisms were explored using immunological methods. The results demonstrated that TFA could promote cell proliferation but inhibit TGF-[Formula: see text]1-induced EMT on A549 cells. TFA attenuated BLM-induced pulmonary fibrosis in mice by modulating inflammatory infiltration and M2 macrophage polarization; it furthermore modulated EMT through regulating the TGF-[Formula: see text]1/Smad pathway. In addition, TFA augmented the expression of the Wnt7b protein, which plays an important role in alveolar epithelium reparation. In conclusion, TFA alleviated bleomycin-induced mouse lung fibrosis by preventing the fibrotic response and increasing epithelium regeneration.

Long-term oral administration of Asarum heterotropoides f. mandshuricum (Maxim.) Kitag. decoction and its aristolochic acid analogs do not cause renal toxicity in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Asarum heterotropoides f. mandshuricum (Maxim.) Kitag. (AH) is widely used to treat influenza, COVID-19, allergic rhinitis, headache, toothache, rheumatoid arthritis, and peptic ulcer. However, its clinical use is controversial due to the concern of aristolochic acid nephropathy (AAN) caused by its component aristolochic acid analogs (AAs). AIM OF THE STUDY: The chronic toxicity of AH decoction and its main components AA IVa (AA-IVa) and aristolactam I (AL-I) was evaluated in mice. MATERIALS AND METHODS: AAs contents in AH were quantitated by liquid chromatography-mass spectrometry. A parallel design was employed to examine the potential chronic toxicity of AH decoction at doses equivalent to 0.5, 1.6, and 5.0 g/kg AH (approximately 10-100 times the clinical doses for humans) and its major AA components at doses equivalent to that in 5.0 g/kg AH to mice after consecutive daily oral administration for 12 and 24 weeks, and at 32 weeks after withdrawal for 8 weeks. RESULTS: AH crude herb contained 2.18 µg/g of AA-I, 48.49 µg/g of AA-IVa, and 14.0 µg/g of AL-I. AH decoction contained 5.45 µg/g of AA-IVa and 2.71 µg/g of AL-I. None of AA-II and AA-IIIa were detected in AH. After long-term administration of AH decoction and its major components AA-IVa and AL-I, mice showed no signs of illness or body weight changes. In addition, biochemical and pathohistological examinations showed that long-term administration of AH decoction and its major components AA-IVa and AL-I did not alter 1) serum levels of glutamic-pyruvic transaminase, glutamic oxalacetic transaminase, alkaline phosphatase, creatinine, and urea nitrogen, 2) renal tissue mRNA expression of kidney injury molecule 1 and neutrophil gelatinase-associated lipocalin, and 3) pathological morphology in the mouse liver, kidney, stomach, and bladder. CONCLUSIONS: AH has no obvious toxicity to mice and is relatively safe when it is used in the form of decoction. AA-IVa and AL-I, the two major AAs in AH, are not toxic to mice at the dose equivalent to that in the high dose of AH decoction. Considering the limited toxicological data on AH, we recommend that AH decoction medication should not overdose and the duration should not be too long.

Citrus junos Tanaka Peel Extract Ameliorates HDM-Induced Lung Inflammation and Immune Responses In Vivo.

In the wake of the COVID-19 pandemic, lung disorders have become a major health concern for humans. Allergic asthma is the most prevalent form of asthma, and its treatments target the inflammation process. Despite significant developments in the diagnosis and management of allergic asthma, side effects are a major concern. Additionally, its extreme heterogeneity impedes the efficacy of the majority of treatments. Thus, newer, safer therapeutic substances, such as natural products, are desired. Citrus junos Tanaka has traditionally been utilized as an anti-inflammatory, sedative, antipyretic, and antitoxic substance. In this study, the protective effects of Citrus junos Tanaka peel extract (B215) against lung inflammation were examined, and efforts were made to understand the underlying protective mechanism using an HDM-induced lung inflammation murine model. The administration of B215 reduced immune cell infiltration in the lungs, plasma IgE levels, airway resistance, mucus hypersecretions, and cytokine production. These favorable effects alleviated HDM-induced lung inflammation by modulating the NF-κB signaling pathway. Hence, B215 might be a promising functional food to treat lung inflammation without adverse effects.

Micronutrient Improvement of Epithelial Barrier Function in Various Disease States: A Case for Adjuvant Therapy.

The published literature makes a very strong case that a wide range of disease morbidity associates with and may in part be due to epithelial barrier leak. An equally large body of published literature substantiates that a diverse group of micronutrients can reduce barrier leak across a wide array of epithelial tissue types, stemming from both cell culture as well as animal and human tissue models. Conversely, micronutrient deficiencies can exacerbate both barrier leak and morbidity. Focusing on zinc, Vitamin A and Vitamin D, this review shows that at concentrations above RDA levels but well below toxicity limits, these micronutrients can induce cell- and tissue-specific molecular-level changes in tight junctional complexes (and by other mechanisms) that reduce barrier leak. An opportunity now exists in critical care-but also medical prophylactic and therapeutic care in general-to consider implementation of select micronutrients at elevated dosages as adjuvant therapeutics in a variety of disease management. This consideration is particularly pointed amidst the COVID-19 pandemic.

Assessment of Neuroendocrine Changes and Hypothalamo-Pituitary Autoimmunity in Patients with COVID-19.

SARS-CoV-2 may affect the hypothalamic-pituitary axis and pituitary dysfunction may occur. Therefore, we investigated neuroendocrine changes, in particular, secondary adrenal insufficiency, using a dynamic test and the role of autoimmunity in pituitary dysfunction in patients with COVID-19. The single-center, prospective, case-control study included patients with polymerase chain reaction (PCR)-confirmed COVID-19 and healthy controls. Basal hormone levels were measured, and the adrenocorticotropic hormone (ACTH) stimulation test was performed. Antipituitary (APA) and antihypothalamic antibodies (AHA) were also determined. We examined a total of 49 patients with COVID-19 and 28 healthy controls. The frequency of adrenal insufficiency in patients with COVID-19 was found as 8.2%. Patients with COVID-19 had lower free T3, IGF-1, and total testosterone levels, and higher cortisol and prolactin levels when compared with controls. We also demonstrated the presence of APA in three and AHA in one of four patients with adrenal insufficiency. In conclusion, COVID-19 may result in adrenal insufficiency, thus routine screening of adrenal functions in these patients is needed. Endocrine disturbances in COVID-19 are similar to those seen in acute stressful conditions or infections. Pituitary or hypothalamic autoimmunity may play a role in neuroendocrine abnormalities in COVID-19.

Where are we with the use of N-acetylcysteine as a preventive and adjuvant treatment for COVID-19?

OBJECTIVE: As N-acetylcysteine (NAC) is promising as a re-purposed drug for the adjunctive or supportive treatment of serious COVID-19, this article aimed to describe current evidence. MATERIALS AND METHODS: A search was performed in PubMed/Medline for "NAC", "viral Infection", COVID-19", oxidative stress", "inflammation", retrieving preclinical and clinical studies. RESULTS: NAC is a pleiotropic molecule with a dual antioxidant mechanism; it may neutralize free radicals and acts as a donor of cysteine, restoring the physiological pool of GSH. Serious COVID-19 patients have increased levels of reactive oxygen species (ROS) and free radicals and often present with glutathione depletion, which prompts a cytokine storm. NAC, which acts as a precursor of GSH inside cells, has been currently used in many conditions to restore or protect against GSH depletion and has a wide safety margin. In addition, NAC has anti-inflammatory activity independently of its antioxidant activity. CONCLUSIONS: Clinical and experimental data suggest that NAC may act on the mechanisms leading to the prothrombotic state observed in severe COVID-19.

Selenium, selenoprotein P, and oxidative stress levels in SARS-CoV-2 patients during illness and recovery.

BACKGROUND: This study aimed to assess tendency of oxidative stress in COVID-19 patients depending on severity. METHODS: The study was conducted with 80 post-COVID-19 disease patients and 40 acutely ill patients. Content of selenium in blood plasma was detected by a fluorimetric method with di-amino-naphthalene using acidic hydrolysis. Selenoprotein P, malondialdehyde and 4-hydroxynonenal and their metabolite adducts were evaluated by spectrophotometric methods using commercial assay kits. RESULTS: Obtained results showed that selenium content in blood for post-COVID-19 disease patients was of a similar lower norm for Latvian inhabitants. Selenium and seleno-protein P contents for acute patients were significantly decreased compared with post-COVID-19 disease patients. CONCLUSION: In conclusion, COVID-19 involves induction of antioxidant systems-in case of severe disease, patients have significantly low concentration of selenium, seleno-protein P and higher level of oxidative stress, which, in turn, confirms the more intense formation of free radicals in the body.

Structural biology of SARS-CoV-2: open the door for novel therapies.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is the causative agent of the pandemic disease COVID-19, which is so far without efficacious treatment. The discovery of therapy reagents for treating COVID-19 are urgently needed, and the structures of the potential drug-target proteins in the viral life cycle are particularly important. SARS-CoV-2, a member of the Orthocoronavirinae subfamily containing the largest RNA genome, encodes 29 proteins including nonstructural, structural and accessory proteins which are involved in viral adsorption, entry and uncoating, nucleic acid replication and transcription, assembly and release, etc. These proteins individually act as a partner of the replication machinery or involved in forming the complexes with host cellular factors to participate in the essential physiological activities. This review summarizes the representative structures and typically potential therapy agents that target SARS-CoV-2 or some critical proteins for viral pathogenesis, providing insights into the mechanisms underlying viral infection, prevention of infection, and treatment. Indeed, these studies open the door for COVID therapies, leading to ways to prevent and treat COVID-19, especially, treatment of the disease caused by the viral variants are imperative.

Xuanfei Baidu Decoction reduces acute lung injury by regulating infiltration of neutrophils and macrophages via PD-1/IL17A pathway.

The pathogenic hyper-inflammatory response has been revealed as the major cause of the severity and death of the Corona Virus Disease 2019 (COVID-19). Xuanfei Baidu Decoction (XFBD) as one of the "three medicines and three prescriptions" for the clinically effective treatment of COVID-19 in China, shows unique advantages in the control of symptomatic transition from moderate to severe disease states. However, the roles of XFBD to against hyper-inflammatory response and its mechanism remain unclear. Here, we established acute lung injury (ALI) model induced by lipopolysaccharide (LPS), presenting a hyperinflammatory process to explore the pharmacodynamic effect and molecular mechanism of XFBD on ALI. The in vitro experiments demonstrated that XFBD inhibited the secretion of IL-6 and TNF-α and iNOS activity in LPS-stimulated RAW264.7 macrophages. In vivo, we confirmed that XFBD improved pulmonary injury via down-regulating the expression of proinflammatory cytokines such as IL-6, TNF-α and IL1-ß as well as macrophages and neutrophils infiltration in LPS-induced ALI mice. Mechanically, we revealed that XFBD treated LPS-induced acute lung injury through PD-1/IL17A pathway which regulates the infiltration of neutrophils and macrophages. Additionally, one major compound from XFBD, i.e. glycyrrhizic acid, shows a high binding affinity with IL17A. In conclusion, we demonstrated the therapeutic effects of XFBD, which provides the immune foundations of XFBD and fatherly support its clinical applications.